What is Greenwich Mean Time (GMT) used for?

Greenwich Mean Time (GMT) is primarily used as a standard reference for timekeeping across different regions of the world. It serves as a baseline from which all other time zones are calculated, making it essential for establishing a uniform time standard globally. This is particularly important in various fields, such as travel, communication, and international business, where synchronization across different time zones is crucial for efficient operations.

By using GMT, people can coordinate activities and ensure that events occurring in different locations occur at the correct local times. For instance, when scheduling meetings or flights that involve participants from various parts of the world, GMT is a reliable reference point that helps avoid confusion and ensures that all parties are on the same page regarding the timing.

In contrast, while the other options touch on important concepts related to financial transactions, shipping, and taxation, they do not pertain to the function of GMT in establishing a global time standard. GMT's primary role is in facilitating the synchronization of time across multiple regions, thereby allowing activities dependent on accurate timekeeping to proceed smoothly and efficiently.